A retaining ring includes a generally annular body having an inner surface to constrain a substrate and a bottom surface, the bottom surface having a plurality of channels extending from an outer surface to the inner surface, and a plurality of islands separated by the channels and providing a contact area to contact a polishing pad, wherein the contact area is about 15-40% of a plan area of the bottom surface.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A retaining ring, comprising: a generally annular body having an inner surface to constrain a substrate and a bottom surface, the bottom surface having a plurality of channels extending from an outer surface to the inner surface, and a plurality of islands separated by the channels and providing a contact area to contact a polishing pad, wherein the contact area is about 15-40% of a plan area of the bottom surface, and wherein each channel includes a recessed region adjacent the outer surface such that the channel is deeper in the recessed region than in a remainder of the channel.
2. The retaining ring of claim 1 , wherein the recessed region and the remainder of the channel each have substantially uniform depth.
3. A retaining ring, comprising: a generally annular body having an inner surface to constrain a substrate and a bottom surface, the bottom surface having a plurality of channels extending from an outer surface to the inner surface, and a plurality of islands separated by the channels and providing a contact area to contact a polishing pad, wherein each channel of the plurality of channels comprises a leading edge and a trailing edge, wherein the leading edge of the channel comprises a first linear segment at a first angle relative to a radial direction from the first linear segment, and wherein the trailing edge of the channel comprises a second linear segment at a second angle from a radial direction from the second linear segment, wherein the second angle is less than the first angle, and wherein the trailing edge comprises a third linear segment that is farther from the inner surface than the second linear segment and that extends substantially perpendicular to the second linear segment.
4. The retaining ring of claim 3 , wherein the channel includes a recessed region adjacent the outer surface such that the channel is deeper in the recessed region than in a remainder of the channel.
5. The retaining ring of claim 4 , wherein the recessed region and the remainder of the channel each have substantially uniform depth.
6. The retaining ring of claim 3 , wherein the first linear segment is oriented at an angle of about 30-60° relative to the radial direction from the first linear segment.
7. The retaining ring of claim 3 , wherein the first linear segment extends across substantially all of a radial width of the bottom surface.
8. The retaining ring of claim 3 , wherein each channel of the plurality of channels comprises an inlet portion at the outer surface, an outlet portion at the inner surface, and a constriction between the inlet portion and the outlet portion.
9. The retaining ring of claim 8 , wherein the constriction occurs at an intersection of the second linear segment and the third linear segment.
10. The retaining ring of claim 8 , wherein the inlet portion is circumferentially longer than the outlet portion.
11. The retaining ring of claim 6 , wherein the second linear segment is substantially radial.
12. The retaining ring of claim 3 , wherein for each channel, the leading and trailing edge are not symmetric across a centerline of the channel.
13. The retaining ring of claim 3 , wherein each channel has the same shape and each island has the same shape.
14. The retaining ring of claim 3 , wherein the plurality of channels are spaced uniformly around the annular body.
15. The retaining ring of claim 14 , wherein there are eight to thirty channels.
16. The retaining ring of claim 3 , wherein the contact area is about 15-40% of a plan area of the bottom surface.
17. The retaining ring of claim 16 , wherein the contact area is about 25-30% of the plan area of the bottom surface.
18. A carrier head, comprising: a base; a flexible membrane coupled to the base, the flexible membrane having a mounting surface for a substrate; and a generally annular body coupled to the base having an inner surface to constrain the substrate and a bottom surface, the bottom surface having a plurality of channels extending from an outer surface to the inner surface, and a plurality of islands separated by the channels and providing a contact area to contact a polishing pad, wherein each channel of the plurality of channels comprises a leading edge and a trailing edge, wherein the leading edge of the channel comprises a first linear segment at a first angle relative to a radial direction from the first linear segment, and wherein the trailing edge of the channel comprises a second linear segment at a second angle from a radial direction from the second linear segment, wherein the second angle is less than the first angle, and wherein the trailing edge comprises a third linear segment that is farther from the inner surface than the second linear segment and that extends substantially perpendicular to the second linear segment.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
July 24, 2017
June 18, 2019
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